SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7df824ad046944a9e0826ad27419198ae9cb0ff1f593beffedf449d25f92a565' 
  AND token = 'relYeboKtAOIeiXy+8A7G3XOicXHa/Hs88rlQRL7O3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}